Valve



- c. A. RoswELL Nov. 21, 1944.

VALVE Filed April 3, 1943 2 Sheets-Sheet l C. A. RSWELL L VALVE Nov. 21,1944.

2 sheets-sheet 2 Filed Aprilis, 1943 INVNTORI @ATTORNEY f. l r PatentedlNov. 21, 1944 VALVE Charles Alfred Roswell, Newburgh, Ind., assigner to Servei, Inc., New York, N.

of Delaware Y., a corporation Application April 3,1943, serial No. ssn-12o lc'laim.- Cc1.se 1) Myinvention relates to' valves, and -it is an object to provide an improved valve for gases as to'organization and method, together with the above'and further objects and advantages utilizing a porous plate and a small amount of` liquid such as, for'example, mercury.

The small amount of mercury, which covers oneface of the porous plate, serves to seal the pores oropenings in the plate to prevent flow of gas therethrough and yet does n ot pass through the pores for the lmaximum pressure differential existing across the plate. 'I'he porous plate may be in the shapeof a disc and i'ormed of any suitable material such as,for example, ceramic material or sintered or fritted glass. found that when a porous 4plate of the character Just described is emp19ed, now of gas win take place through suc plate -even when the pres'- sure differential across the plate is equivalent only to a few millimeters of mercury.

c When a porous plate is provided in a vertically extending portion of ay tube or conduit and the pressure existing above the mercury and top side of the plate vis less than that existing` below the plate, gas will flow upward through the porous plate and bubble through the mercury. However,

when the pressure vexisting above the mercury and top side ofthe porous plate is substantially equal to or greater than that prevailing below the plate, the lmercury is effective to close and vent flow of gas therethrough.

It is another object ofthe invention to proseal the pores or openings in the plate and previde a valve of the character described which can be tilted into -any position without losing or spining mercury and with no Ieakage ofl gas through the porous-y plate. A tiltable valve possesses many advantages in that such a valve may belinstalled in apparatus at a. factory, so that additional installation work on-theapparatus in tiltable mercury porous plate valve can be con- I have thereof,- will be better understood by reference tothe following description taken in connection with the accompanying drawings in which Fig.

1 more or less diagrammatically illustrates a refrigeration mtem embodying my invention; Fig. -2 is an enlarged fragmentary view, in section, of parts shown in Fig. 1 to illustrate the manner `inv which non-condensible gases are transferred within the refrigeration system; Fig. 3 is an enlarged fragmentary view, in section,

.of parts of Fig. 1 to illustrate more clearly the mercury porous plate valve embodying the invention; and Fig. 4 is a fragmentary view illustrating an embodiment of the invention in which the valve-can be tilted to any position without spilling or losing mercury.

Referring to Fig. 1, the inventionis embodied in a two-pressure absorption refrigeration' system like that described in United States Letters Patent No. 2,282,503 of A. R. Thomas and P. P. Anderson, I

Jr.,- granted May 12, 1942. In asystem of this type liquid ,refrigerant such as, for example,

' ment i0 ows therefrom to an absorber IS in which the vapor is absorbed into a liquid abvtheiieldor ultimate place of use in order to connect the valve, is avoided. This is particularly true in refrigeration apparatus in which al nected in the apparatus when the latter is bei ing built, Iwhereby the necessityl of providing other types of mechanical valves and connections for the apparatus for the transportation period only is elimlnatedn ,f

It is a further object of the invention to pro- .vide a mercury porous plate valve for use in refrigeration apparatus of thev kind operating at a partial vacuum and fromv which non-condensible gasesare exhausted to the atmosphere. 'I'he no vel features which-are believed to be characteristic of my invention are set forth with partimilarity in the claim. The invention, both water, is introduced into vthe upper part of a cooling element I0 from a condenser Il through a path of `ow including a U-shaped tube I2 and a, chamber I 3. 'I'he liquid refrigerant evaporates in cooling element i 0 with consequent absorption of heat from the surroundings, as from a stream of air owing over the exterior surfaces of the-tubes I4 and fins l5 of the evaporator. 'I'he refrigerant vapor formed in cooling elesorbent such as, forexample, a solution of lithium bromide. n l

' The absorption liquid enriched in refrigerant is conducted from absorber i6 to a generator I7 in'a path of flow including a conduit I8, liquid heat exchanger I9, conduit 20, vessel 2| and conduit 22. Within the generator I1 are disposeda plurality of riser tubes 23 enveloped by a chamber formed by theouter shell to which steam is supplied through a conduit 24 from a suitable source of supply. The heating of the riser tubes 23 by the steam 'causes refrigerant vapor to be expelled from the absorbent, and such expelled vapor is e'ective to raise liquid absorbent by gas or vapor lift. liquid action.

l The expelled vapor passes from the upper ends -of the riser tubes 23 into a vapor separator 25 vand thence `iows 'through a conduit 26 to condenser Il in which the vapor is liqueed. l Liquid .refrigerant formed in condenser Il 'ows through be utilized to eiiect cooling action of the refrigerant -ing element in absorber- I6 is taken up by a cooling medium such as, for example, water, which flows upward through vertically disposed pipe banks 29 in the absorber. The cooling water is introl`duced into the lower end of the pipe banks through a conduit 30 and is discharged from the upper end of the pipe banks through a conduit 3l. The conduit 3l is connected to condenser II, so that the cooling water may also o! condenser II. The cooling water is discharged from condenser II through a conduit 32.

The system operates at a partial vacuum with generator I1 and condenser II operating at one pressure and cooling element III and absorber I6 operating at a lower pressure. The pressure diierential between the high and lower pressure sides` of the system is maintained by liquid co1- umns, as disclosed in the aforementioned Thomas and Anderson patent, which may be considered as being incorporated in this application and `.to which reference may be made, if desired, for a detailed description of the refrigeration apparatus. A

During operation of the' refrigeration system, non-condensible gases may collect therein, and in condenser II such gases flow toward the deadend or bottom part of the condenser. In order to transfer the non-condensible gases from condenser I I to cooling element II), a liquid trap 33 is provided in U-tube I2. Liquid formed in condenser II ilows into trap 33, and, when the trap isA completely lled with liquid, such liquid is siphoned from the trap into the downleg of the U-tube I2. 'I'he liquid level in the downleg of U-tube I2 is below the trap 33 since the pressure in condenser II is considerably higherA than the pressure in cooling element I0. Since the liquid level in the downleg of the U-tube I2 is between the trap 33 and 'extreme lower end, gas above the liquid level in the downleg is trapped by the liquid siphoned from the (liquid trap 33. After liquid is siphoned from trap 33, gas can pass from the bottom part of condenser'l I through the open trap into the downleg of U-tube I2. When liquid is again siphoned into the downleg of. U-tube vI2 from trap 33, gas is again trapped by the siphoned liquid. The gas segregated between successive bodies of liquid siphoned from trap 33 is compressed by the siphoned liquid and passes through U-tube I2 from condenser II to cooling ele'- ment III.

. The non-condensible gases in the lower pressure side of the system, that is, in the cooling element In and absorber I3, are carried to the bottom part of the absorber by the sweeping vapor. By sweeping action it is meant that the downward movement is imparted to the non-condensible gases by the high velocity refrigerant vapor flowing from cool- III into the absorber Ii.. The non"- to the bottom part condensible gases are swept substantially mid-way oi absorber I3 to a region between the ends thereof.` I

'The heat liberated in auxiliary In order to transfer non-condensible gases from absorber I6 to avertical conduit 34 and vessel 35, which may be referred to as inactive parts of the system, an auxiliary absorber 36 is provided into which the non-condensible` gases collecting in the bottom part of the absorber I6 are drawn through a conduit 31.

Absorption liquid is introduced into auxiliary absorber 36 through a 'conduit 31' which is connected at its upper end to conduit 23. In this way a portion of the absorption liquid flowing to the upper part of absorber I3 is diverted from conduit 28 into conduit 31. After passing through a screening 33 in auxiliary absorber 36, the diverted absorption liquid passes through an opening 39. The liquid discharged from opening 39 strikes a plate 40 and then flows downward over the exterior surface of a coil 4I.

With this arrangement the gases withdrawn from absorber I8 through conduit 31 are brought into intimate contact with diverted absorption liquid in auxiliary absorber 3B. Refrigerant vapor accompanying the non-condensible gases withdrawn from main absorber I6 is absorbed 'into absorption liquid in auxiliary absorber 36.

taken up by cooling water in coil 4I which is supplied through conduit 42 from conduit 30, and which is discharge through conduit 43 to conduit/3|. l i

A vertical tube 44, which maybe referred'to as a fall tube pump, is connected at its upper end to the bottom part of auxiliary absorber 36 and at its lower end to the bottom part of the vertical conduit 34. Liquid intermittently fills the upper bent end of vertical tube 44 and siphons thereamorption liquid in the from, whereby small quantities of non-condensible gases are withdrawn from the bottom part of the auxiliary,absorber` and trapped between successive bodies or slugs of liquid, as shown in Fig. 2. The internal diameter of tube 44 is such that gas and liquid cannot pass each other while ilowing down through the conduit. condensible gases are discharged from the low end of tube 44 into vertical conduit 34 and freely bubble upwardly through liquid in the latter. As the quantity, of non-condensible gases trapped in vertical conduit 3'4 and vessel 35 increases, the

Y liquid level in conduit 34 falls with the gases diS- placing liquid from the bottom of conduit 34 through a connection 45' into conduit23.

when the liquid is at a maximum level in conduit 34,.as at the level p, for example, the pressure in vessel 3l and upper partof conduit 34 is in'equilibrium with the, vapor pressure of the conduit. In a reinseration system like that described above and having an ice melting capacity o! about nve tons, and in which a solution of lithium bromide of about 55% concentration by weight is employed, the pressure in vessel 35l and above the maximum liquid level p in conduit 34 is less than about twenty-five millimeters of mercury. As liquid in vertical conduit 34 is displaced by non-condensible gases transferred thereto, the liquid in the conduit 34 falls until it reaches-the minimum referred to is approximately millimeters of L mercury.- .I f a ,Ihe non-condensible gases in vertical conduit absorber 36 is ascauo 34 and vessel 35 are exhausted from the ref eration syste to the atmosphere by a suitable `vacuum pump such as, for example, a simple water aspirator type ofpump 45. The vacuum pump 45 is connected by a conduit 43, vessel 41 l and conduit 43 to' vessel 35 for withdrawing noncondensible gases from the system. I'he conduit 431s connected to the converging side of the to the vessel 35 isprovided a valve 52 embodying -my invention which is effective to maintain the system at a low pressure and at the same time allows Vnon-condensible gases lto pass therethrough when the vacuum pump 45 is operated.

As shown most clearly in Fig. 3, the valve 52 comprises an elongated vertical vessel 53 to the inner wally of which is secured a porous plate or disc 54.l A small body 55 of a liquid such as, for

` example, mercury, rests upon the porous plate 54.

The vessel 53 may be formed of non-porous glass and the disc 54 may consist of a porous body of ceramic material, fritted or sintered glass particles, or glass strands. vl'orous plates formedl o1' fritted or sintered glass are well known and described in United States Letters Patent Nos. l'

1,620,815, 2,115,748 and 2,136,170.

When it is desired to effect removal of noncondensible gases,i from the refrigeration system, y

the valve 5I is opened so that water will be supplied to nozzle 49 of the vacuum pump 45. The water passing through the nozzle 49 acquires a high` velocity, whereby a suction eilect'is produced in the upper part of valve 52 which is in communication with the pump through a part of conduit 48, vessel 41 and conduit 45. Assuming that the liquid level is at m in conduit 34,

and the pressure in vessel v is -about 100 millikmeters of mercury, non-condensible gases will pass upward through the porous plate 54 and bubble through the body 55 of mercury when the partial pressure produced by the vacuum pump 45 is only a few millimeters of mercury below that existing in vessel 35. Thus, Awherrtlie depth of the body of mercury is about two millimeters and the pressure in the upper part'of valve'52 is approximately 95 millimeters of mercury while the pressure in vessel 35 is about 100 millimeters of mercury, the non-condensible gases will pass through the porous plate 54, conduit 48, vessel 41 and conduit 46 to the vacuum pump 45 from 'As the non-condensible gases are withdrawn from vessel 35 and conduit 34, the liquid level rises in the latter until the upper or maximum liquid level p is reached. AWhe/n this occurs, the valve 5| is closed to shut oft-| the vacuum pump 45. When the vacuum vpump is shut oi, water in the venturi may be forced into conduit 46 by the atmospheric. pressure which is momentarily greater than the pressure existing in that conduit. It is for this reason that conduit '45 includes an inverted U-shaped portion'having one leg thereof extending downwardly within vessel 41 and terminating in the lower part thereof, as

` shown in Fig. 3. With this arrangement vessel 41 srves as a water trap, so that there will not ywhich the non-condensible gases are discharged.A A to the atmosphere.

be any likelihood of water being drawn up through conduit 43 into the upper part of'- the valve 52.

With the vacuum pump '45 no longer operating, the body 55 of mercury in valve 52 is then subjected to atmospheric pressure-while the pressure in vessel 35 and below the porous plate 54 is very small and in the neighborhood of about 25,milli meters of mercury. A very small pressure in this range can readily be produced with a water type aspirator'pump to which water at a temperature as high as F. is supplied at a line about 30 pounds per square inch.

Hence, the pressure existing across the porous plate 54 is approximately one atmosphere and for this pressure differential the body 55 of m'ercury eiectively seals` and closes off the pores or openings in the porous plate. In order that mercury will not llow through the DOIBS in the porous plate 54 when the pressure existing across the plate is about` one atmosphere, I have found pressure of that the average diameter of thepores or open- In Fig. 4l I have illustrated a valve 52'which dilers from that shown in Fig, 3 and described above in that'such valve is tiltable to any position. 'I'he valve 52' is connectedfln a conduit 48' corresponding to conduit 48 in Figs. 1 and 3. The valve 52' includes an enlarged cylindrical portion 53 within which extends a tubular hollow stem 5 1. The diameter of stem 51 is substantially the same as' that of conduit 48' to which the bottom of the valve is connected.

'I'he hollow stem 51 terminates in the upper part of the enlarged cylindrical portion 55 and is closed by a porous plate 54 of about the same porosity as the plate 54 in Fig. 3. Above the porous plate 54' and at the narrow portion 58 of valve 52' is provided a second porous plate or -disc 59. Both the porous plates 58 and 59 may vof mercury will always cover the porous plate 54' irrespective\, of the position of valve 52. While the pores in the porous plate 54 in the instant embodiment should be 20 microns or less in diameter, so that the mercury will not pass through the pores for the maximum pressure differential of about one atmosphere across the plate 54', the porous plate. 59 can be of greater porosity such as microns, for-example, because it is only provided to keep mercury from spilling from valve 52' when the latter is tilted from the vertical.

Further, by employing a porous plate 59 having as high a porosity as possible, the resistance developed by valve 52' to flow of gas therethrough that they are self-regulating, that is, the height of the body of mercury above the porous plate can determine the minimum pressure that can be produced below the porous plate, even though the vacuum pump iscapable of producing a pressure below that minimum pressure. The valve 52', of course, possesses the additional advantage that it can be tilted to any position without permitting ilow of gas therethrough and with no loss of mercury. By keeping the body 55' oi mercury trapped between the porous plates 5|' and 59, the mercury is always kept clean.. Since the valve 52' can be tilted to any position, this valve can be connected in the refrigeration apparatus at the factory, whereby the necessity' of making temporary connections at the factory and subsequently installing the in the eld, is eliminated. While the valve. 52

` can be tilted to any position, I prefer to use the mercury DOI'OUS plate Valve.

manner illustrated in assai-1o valve in an upright or vertical position in the Figli.

While several embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that various modications and changes may be made without departing from the spirit and scope of the invention, as pointed out in the following claim.

What is claimed is:

In refrigeration apparatus operable below atmospheric pressure and having a part in which non-condensible gases are collected, a vacuum pump, a conduit connectingsaid pump and said part, said vacuum pump being operative to exhaust non-condensible gases from said part to the atmosphere when the pressure produced by said pump is less than the pressure prevailing in said part, valve structure hermetically sealed in said `,conduit for preventing atmospheric air from entering said part when said pump is no longer operating, said valve structure comprising a porous body and a body of mercury covering a surface of said body, and said valve structure being so constructed and arranged that mercury cannot spill therefrom .and will always cover the surface of said porous body irrespective of the position of saidvalve structure.

. CHARLES ALFRED ROSWEIL. 

